Phipli
Well-known member
Hello folks!
I've been tidying up a Performa 630 DOS Compatible that was found at a dump a good few years ago, it has some corrosion damage due to being left outside (rust on ports, couple of corroded pins on the processor, some relatively minor blemishes here and there, plus it looks like the battery leaked a little. The most notable issues were that the internal CD didn't work and that there is no audio. It also sporadically crashes - it either freezes, or progressively gets slower until it basically stops... as if something was triggering millions of interrupts. The computer functions perfectly if I swap in another P630 logic board (don't ask, my dad likes them, so we have spares), but the troublesome board is the only DOS board. The DOS logic boards are different - they have two RAM slots populated is the obvious difference, but they also have additional holes for the DOS board's standoffs, and an additional connector, I believe for the pass-through video (the footprint doesn't even exist on the regular P630). @Bolle mentioned that the DOS 630s have more in common with the P580 boards.
So far I have replaced the CPU with one that doesn't have a broken pin (see "Sad CPU.jpg"), done a bodge wire repair of the SCSI termination for the internal CD ("Bodge 1 (SCSI).jpg"), done a bodge repair on a broken / lifted trace near the serial ports ("Bodge 2 (Serial).jpg"), renewed the solder on some pins for U24 because it looked crusty ("U24 Resoldered.jpg")... and recapped it ("LB Top Recap.jpg"). Not because it looked like it needed it, but because I thought that there was a chance that dodgy audio might be due to caps that forgot what capacity they should be.
I continuity tested the battery damage, and had continuity on all vias other than one of the two (related) vias highlighted in "Battery Damage 2.jpg". I realise that there is a chance that the probes might have helped with this, but I suspect the pins all relate to internal SCSI termination... which works now
Given the audio works with another logic board in the computer, the fault is almost certainly on the logic board. Given the CD audio pass-through doesn't work, it is likely in the mixing / amplification stage or later of the audio system. I think this means U1 (DFAC II?) is a possible suspect, but it is a custom chip unfortunately. See "Arch Audio.png" (Thanks George).
I've attached a number of photos that might be helpful. Are there any known causes of audio issues on 630s or similar machines? Does anyone have any suggestions?
Thoughts welcome, solutions extremely welcome
I've been tidying up a Performa 630 DOS Compatible that was found at a dump a good few years ago, it has some corrosion damage due to being left outside (rust on ports, couple of corroded pins on the processor, some relatively minor blemishes here and there, plus it looks like the battery leaked a little. The most notable issues were that the internal CD didn't work and that there is no audio. It also sporadically crashes - it either freezes, or progressively gets slower until it basically stops... as if something was triggering millions of interrupts. The computer functions perfectly if I swap in another P630 logic board (don't ask, my dad likes them, so we have spares), but the troublesome board is the only DOS board. The DOS logic boards are different - they have two RAM slots populated is the obvious difference, but they also have additional holes for the DOS board's standoffs, and an additional connector, I believe for the pass-through video (the footprint doesn't even exist on the regular P630). @Bolle mentioned that the DOS 630s have more in common with the P580 boards.
So far I have replaced the CPU with one that doesn't have a broken pin (see "Sad CPU.jpg"), done a bodge wire repair of the SCSI termination for the internal CD ("Bodge 1 (SCSI).jpg"), done a bodge repair on a broken / lifted trace near the serial ports ("Bodge 2 (Serial).jpg"), renewed the solder on some pins for U24 because it looked crusty ("U24 Resoldered.jpg")... and recapped it ("LB Top Recap.jpg"). Not because it looked like it needed it, but because I thought that there was a chance that dodgy audio might be due to caps that forgot what capacity they should be.
I continuity tested the battery damage, and had continuity on all vias other than one of the two (related) vias highlighted in "Battery Damage 2.jpg". I realise that there is a chance that the probes might have helped with this, but I suspect the pins all relate to internal SCSI termination... which works now
Given the audio works with another logic board in the computer, the fault is almost certainly on the logic board. Given the CD audio pass-through doesn't work, it is likely in the mixing / amplification stage or later of the audio system. I think this means U1 (DFAC II?) is a possible suspect, but it is a custom chip unfortunately. See "Arch Audio.png" (Thanks George).
I've attached a number of photos that might be helpful. Are there any known causes of audio issues on 630s or similar machines? Does anyone have any suggestions?
Thoughts welcome, solutions extremely welcome
